Two layettes plus a gift for Mom -- you are a good friend!
IMO the shawl is a nice idea. It's a "neutral" design that can be used many ways. If she's young and chic, she'll find her own way to wear it. She might throw it over something lightweight or low-cut for evening. Or wear it with a sweater and jeans while she's taking the twins for a walk. Or even use it to decorate a couch.
I would stay with neutral colors -- cream or black or warm beige or gray. They're more versatile and more likely to be pleasing to a fashion-conscious person.